This invention generally relates to the problems of detecting ocular disorders effectively and reliably in a patient. More specifically, this invention is concerned with the objective detection of ocular disorders so that uncooperative patients such as, for example, infants, pre-school children, infirm persons or the like can be expediently examined for ocular disorders and diseases.
Conventional devices which measure the depth of the optic fundus have been proposed, such as, for example, those disclosed in U.S. Pat. Nos. 3,524,702; 3,639,041; 3,791,719; and 3,819,256. The conventional devices for measuring the fundus depth of an eye utilize the general principle of retroflecting collimated light to determine the refractive index of the eye. However, most conventional devices utilize a complicated system of lenses together with either a mechanical or electrically operated focusing system. The additional elements provided in the conventional devices necessarily increase the cost of providing the devices to ophthalmologists, optometrists, hospitals or the like.
Most conventional devices require that a patient being examined stare either into the device or at a fixation point for a period of time so that the proper fundus reflex can be determined. Therefore, the length of time necessary to provide an accurate reading utilizing conventional devices is not conducive to the examination of uncooperative patients, such as, for example, infants, pre-school children, infirm persons or the like.
Additionally, conventional devices basically utilize two separate systems for determining the refractive index of the patient's eyes. Thus, the number of operational components is necessarily increased by providing two separate systems in a single ophthalmological device. As noted above, an increase in the number of operational components will necessarily increase the cost of the device and, thus, could make such a device cost prohibitive for certain organizations, schools or the like.
According to the present invention, however, there is provided an apparatus and method which can objectively determine ocular disorders by measuring the relative intensities of coaxially retroflected collimated light from a patient's eyes. The apparatus and method according to the present invention only requires that a patient look into the apparatus for a brief period of time, thereby enabling the examining ophthalmologist, optometrist or technician to obtain an accurate detection of ocular disorders. The device according to the present invention is relatively simple and therefore, can be manufactured inexpensively when compared to conventional devices utilized for measuring the fundus reflex of the eye.
The fundus reflex observable in the pupils of the eye in a normal patient when the eyes are coaxially illuminated is equal if the patient's eyes are parallely aligned and structurally normal. Any deviation from the normal in either alignment or structure will manifest itself in abnormal and/or unequal fundus reflexes. The apparatus and method according to the present invention enables an ophthalmologist, optometrist or technician to objectively compare the fundus reflexes of each eye simultaneously so that most ocular abnormalties and disorders of the eye and visual system can be readily detected. Additionally, the apparatus and method of the present invention may be utilized with minimal cooperation of the ocular patient by requiring the patient to only look briefly into the apparatus.
The fundus light reflex of both eyes can be measured and compared so that most ophthalmic pathological disorders can be objectively detected. Any quality or deviation from the normal under test circumstances can be objectively measured when the patient suffers from the following general ophthalmic disorders: Strabismus; Anisometropia; Anisocoria; Nystagmus; Opacities and/or abnormal light transmission of the ocular refractive media as well as most other pathological conditions of the refractive media; Exophthalmus; Enophthalmus and other abnormal positions of the eyeball; and many retinal and choroidal diseases.
Therefore, according to the present invention an apparatus and method are provided that are particularly adapted for screening eye diseases and ocular disorders in infants, pre-school children, infirm persons and other uncooperative patients. The apparatus according to the present invention is relatively simple and can be easily and inexpensively manufactured so that a variety of organizations will be able to obtain the apparatus and administer the test method for early detection of ocular disorders. The device is constructed so that an ocular screening test can be performed by relatively unskilled persons after minimal training so that schools, clubs or other organizations can be equipped to detect any early signs of ocular disorders. Additionally, a device according to the present invention is provided which is easily and effectively operated to monitor changes and progress in the condition of an ocular patient. Further advantages of using a device and method according to the present invention will be readily apparent to those of ordinary skill in the art when examining the detailed description of the invention.